From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f43.google.com (mail-pj1-f43.google.com [209.85.216.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E10062C87 for ; Wed, 13 Oct 2021 19:06:00 +0000 (UTC) Received: by mail-pj1-f43.google.com with SMTP id om14so2958435pjb.5 for ; Wed, 13 Oct 2021 12:06:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=nXWn+C65G2sncjtbdtLGu+sNNu6Ws1SqzBL/4RC9QLU=; b=erKHCPbwnNJ+dbqyPQbIehybLasan69a6yMxEWXzryT+WjIUFwYywkEcbu3sK2q+sy B4xybss34Pz4s5MJQv6FtWcW/s4zV23O6TAK3lHCVve6FUWq6ON/yXJ7bVJmDYQv+KnY mvgU1s3Cf/SkHLYm5h2XUwvQO6CkkSvIVSm7Y= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nXWn+C65G2sncjtbdtLGu+sNNu6Ws1SqzBL/4RC9QLU=; b=pK9jQsS+sLAV5cLavhcktvHQ+a3771pddoq6MXS5KWmXX/urDq1pI4E8mEue24Z6+N zMl+GnL1tCu1zDXLr4WiWLjDpwvLDCxt8W1bCgqn1DdDaunVqtJLIEJ0EKoV58uX52Vt l/qW500cnPg7QxjuwQqKQJVztVIzXXNSCIdxtUrGc0wbCyqwoWFiETCCPx8vbsen9/Hb yKqnbcNGuT+tb83a1djmxxHrV/TdZQLEC5M6vRsG2oGptvCXn7tEoq7Tipxb7Wk2OlkC 9zi2ZgVLBJZ4UH15W8JtJ7dLyeZSzF3Tx5lbK7eryEbOxVs2ylJLzGx5QX/wPewCtSMi qc/w== X-Gm-Message-State: AOAM533zEC9uM/1gb7QSRSnLbqfObvlg84rdeBeH8Dn6hD2IOAE5Yr6a /CAOpE0a4z550kcpdCT/ze3dJg== X-Google-Smtp-Source: ABdhPJxDuBX+/M7L1lKdmAL5VUL05XQ8QINY1cDE3k+ssDyXnVzf+flLTDS1Ptu7vFglJAdHNPg/Tw== X-Received: by 2002:a17:90a:708c:: with SMTP id g12mr15274111pjk.13.1634151960400; Wed, 13 Oct 2021 12:06:00 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id o72sm235042pjo.50.2021.10.13.12.06.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Oct 2021 12:06:00 -0700 (PDT) Date: Wed, 13 Oct 2021 12:05:59 -0700 From: Kees Cook To: Sami Tolvanen Cc: x86@kernel.org, Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor , Nick Desaulniers , Sedat Dilek , Steven Rostedt , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v5 10/15] x86/purgatory: Disable CFI Message-ID: <202110131204.9978A005FC@keescook> References: <20211013181658.1020262-1-samitolvanen@google.com> <20211013181658.1020262-11-samitolvanen@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211013181658.1020262-11-samitolvanen@google.com> On Wed, Oct 13, 2021 at 11:16:53AM -0700, Sami Tolvanen wrote: > Disable CONFIG_CFI_CLANG for the stand-alone purgatory.ro. If there's a v6, this commit log might do well to have a "why" added. I assume it'd be something like: ... because purgatory is not running with a full kernel mapping with jump tables, etc... Reviewed-by: Kees Cook > > Signed-off-by: Sami Tolvanen > Reviewed-by: Nick Desaulniers > Tested-by: Nick Desaulniers > Tested-by: Sedat Dilek > --- > arch/x86/purgatory/Makefile | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile > index 95ea17a9d20c..911954fec31c 100644 > --- a/arch/x86/purgatory/Makefile > +++ b/arch/x86/purgatory/Makefile > @@ -55,6 +55,10 @@ ifdef CONFIG_RETPOLINE > PURGATORY_CFLAGS_REMOVE += $(RETPOLINE_CFLAGS) > endif > > +ifdef CONFIG_CFI_CLANG > +PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_CFI) > +endif > + > CFLAGS_REMOVE_purgatory.o += $(PURGATORY_CFLAGS_REMOVE) > CFLAGS_purgatory.o += $(PURGATORY_CFLAGS) > > -- > 2.33.0.1079.g6e70778dc9-goog > -- Kees Cook